The one thing we have learnt about barriers is that they need to be consistent within a game. If we are to create a plausible game world, then we need to ensure players are instantly able to differentiate between what they can and cannot do.
We do this every day in real life. For example, if you come across a small railing, you can simply step over it, but if come to a huge wall then it's safe to say that unless you are Spider-Man, you aren't going anywhere.
This in itself poses an interesting dilemma. What if you do have a game where the main character can behave like Spider- Man. How do you go and define boundaries, in this instance?
Spider-Man can walk over any object, so simply creating an impassable wall will not work here and, as such, a feasible alternative would need to be devised. Simply having a wall which is suddenly - and for no reason - impassable is not going to go down well with players.
So how do we go about making plausible boundaries within a game? Well, let us make them so that they fit in with the game and that players are able to instantly tell that they are unable to proceed any further for a reason.
Players should be able to tell if a barrier is destructible or not and doorways ought to give the indication that they can be opened. The dreaded invisible barriers need to just (excuse the pun) vanish altogether, while senseless boundaries can easily be modified to fit in with the game.
If the environment is going to block the player, why should we allow them to work themselves halfway through an impassable boundary, and give the impression they can surmount it? Stop players right at the start before they spend frustrating moments thinking they can achieve what is impossible.
Of course, this may simply come about through a quick case of trial-and-error, whereby the player walks up to two different types of boundary and finds out by interacting with the barrier which one allows passage or not. However, because they look different, the player now has a good frame of reference and is able to quickly tell the difference the next time it is encountered.
Next time you play a game, no matter what it is, take a look at where and how you are held back in certain areas. Does it make sense? Did you just come across something similar a while back that let you pass and if so, how does it now feel to be caged in and trapped by the exact same thing now?
Our game design should ensure that we treat the player to a great game on all levels. Simply blocking their way with a barrier that makes no sense is not going to achieve this. Not only will this make the game seem unrealistic, it will also have a detrimental effect on the style of play.
Players will become fed up at trying to hunt for that one "breakable" barrier in a sea of barriers or the one door among a corridor of identical doors which will open up into another part of the level.
I'm sure we've all come across that odd little quote from players who point out a neat little feature in the game that they played - something that was unexpected. This is what creating meaningful boundaries will hopefully achieve.
It is an addition that attempts to imbue the player with a sense that the game is built around them and that everything in it is there to ensure that the player has a good time. After all, isn't that what really counts?